Ok enough with Illaoi plz just look at this riot I insist!

I just played in a game vs an Illaoi (not this video, this video was one I found on youtube) as Pantheon, im up 3-1 in kills up 15cs freshly back from ganking a lane with my ult i shoped come into the lane with a good lead. Illaoi wants to fight me, I dodge her Q and counter with my spear toss and jump on her and take her to just under half hp instantly, then she just presses R W and I'm dead before I know it. Now keeping in mind that my situation that happen was I'm way ahead on items and I came from the shop. I even had ignite on her, I dodged her tentacle hit and she still gets rewarded with instantly winning the fight by pressing R and W. I don't understand how you guys can continue to be ok with this champions stats. I mean if that video above isn't enough proof. She is 1v5 there and gets cc'd hard. and lives killing all 5 of them. Even later to give another example, I got a randuins omen some defenses 3k hp on me 170 armor. Illaoi grabs my spirit, and her team all hit it, I lose 2k hp for getting hit with 1 skills shot, and being out of range for all of them to attack me. Can you please explain to me how this makes sense as a kit and with those stats? I really thought maybe this patch something would get done to fix this, and it didn't. It Just makes no sense, she did all of this damage having 1 damage item (black cleaver).